Presently, there are a variety of printed circuit boards (PCB), which are widely used. In a high-frequency and high-speed PCB, metal matrix embedded in the PCB is grounded mainly by conducting with an inner geoelectric layer.
In the prior art, the metal matrix is in conduction with the inner geoelectric layer via wires. In practice, it is found that, although the existing connecting way enables the geoelectric layer to be connected to the metal matrix, this connecting way has poor reliability, often resulting in broken circuit, and has unstable transmission performance for a high frequency signal.